[Acute, chronic or physical urticaria. What causes the hives?]

Urticaria is characterized by strongly pruritic wheals and in some cases, angioedema. On the basis of a careful case history, the type of urticaria presenting can usually be determined. In the case of the acute form, no complicated diagnostic work-up is necessary. Treatment is symptomatic: the use of ASA should be avoided, while an acute infection requires treatment. When there is recurrent angioedema, chronic urticaria and physical forms, a multitude of triggering factors must be considered. In many cases, symptoms may persist for years. Symptomatic treatment with antihistaminics is often inadequate, but long-term treatment with glucocorticoids should be avoided on account of their side effects. For this reason, further diagnostic work-up is usually necessary and, where indicated, treatment should be initiated by a dermatologist with specialist training in allergology.